Intrathecal baclofen, a GABAB receptor agonist, inhibits the expression of p-CREB and NR2B in the spinal dorsal horn in rats with diabetic neuropathic pain

2014 ◽  
Vol 92 (8) ◽  
pp. 655-660 ◽  
Author(s):  
Peng Liu ◽  
Wen-Ya Guo ◽  
Xiao-Nan Zhao ◽  
Hui-Ping Bai ◽  
Qian Wang ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Dorsal Horn ◽  
Receptor Agonist ◽  
Spinal Dorsal Horn ◽  
Gabab Receptor ◽  
Intrathecal Baclofen ◽  
Mrna Levels ◽  
Diabetic Neuropathic Pain ◽  
Withdrawal Threshold ◽  
Spinal Dorsal

This study aimed to investigate the effect of baclofen, a γ-aminobutyric acid B (GABAB) receptor agonist, on the expression of p-CREB and NR2B in the spinal dorsal horn of rats with diabetic neuropathic pain (DNP). The DNP rats, which were successfully induced with streptozocin, were distributed among 3 groups that were treated with saline (D1 group), baclofen (D2 group), or CGP55845 + baclofen (D3 group) continuously for 4 days. The rats induced with saline and subsequently treated with saline were used as controls (C group). The times for the paw withdrawal threshold and thermal withdrawal latency of the D1 group were lower than those for the C group, and were significantly increased after baclofen treatment, but not when GABA receptor was pre-blocked with CGP55845 (D3 group). Increased protein expression levels of NR2B and p-CREB and mRNA levels of NR2B were found in the D1 group when compared with the controls. Baclofen treatment significantly suppressed their expression, bringing it close to the levels of controls. However, in the D3 group, the expression of p-CREB and NR2B were still significantly higher than that of the controls. Activation of GABAB receptor by baclofen attenuates diabetic neuropathic pain, which may partly be accomplished via down-regulating the expression of p-CREB and NR2B.

scholarly journals Hypersensitivity of Spinothalamic Tract Neurons Associated With Diabetic Neuropathic Pain in Rats

2002 ◽  
Vol 87 (6) ◽  
pp. 2726-2733 ◽  
Author(s):  
Shao-Rui Chen ◽  
Hui-Lin Pan
Keyword(s):  
Neuropathic Pain ◽  
Dorsal Horn ◽  
Spinal Dorsal Horn ◽  
Thermal Hyperalgesia ◽  
Diabetic Rats ◽  
Projection Neurons ◽  
Diabetic Neuropathic Pain ◽  
Spinothalamic Tract ◽  
Functional Changes ◽  
Spinal Dorsal

Diabetic neuropathic pain is often considered to be caused by peripheral neuropathy. The involvement of the CNS in this pathological condition has not been well documented. Development of hypersensitivity of spinal dorsal horn neurons is involved in neuropathic pain induced by traumatic nerve injury. In the present study, we determined the functional changes of identified spinothalamic tract (STT) neurons and their correlation to diabetic neuropathic pain. Diabetes was induced in rats by intraperitoneal injection of streptozotocin. Hyperalgesia and allodynia were assessed by the withdrawal responses to pressure, radiant heat, and von Frey filaments applied to the hindpaw. Single-unit activity of STT neurons was recorded from the lumbar spinal cord in anesthetized rats. The responses of STT neurons to mechanical and thermal stimuli and the sensitivity to intravenous morphine were determined in diabetic and normal rats. In 12 diabetic rats, mechanical allodynia and hyperalgesia, but not thermal hyperalgesia, developed within 2 wk after streptozotocin injection and lasted for ≥7 wk. Compared to the 32 STT neurons recorded in normal animals, the 37 STT neurons in diabetic rats displayed a higher spontaneous discharge activity and enlarged receptive fields. Also, the STT neurons in diabetic rats exhibited lower thresholds and augmented responses to mechanical stimulation. Intravenous injection of 2.5 mg/kg of morphine suppressed significantly the responses of STT neurons to noxious stimuli in 12 nondiabetic rats. However, such an inhibitory effect of morphine on the evoked response of STT neurons was diminished in 14 diabetic animals. This electrophysiological study provides new information that development of hypersensitivity of spinal dorsal horn projection neurons may be closely related to neuropathic pain symptoms caused by diabetes. Furthermore, the attenuated inhibitory effects of morphine on evoked responses of STT neurons in diabetes likely accounts for its reduced analgesic efficacy in this clinical form of neuropathic pain.

Sirtuin 1 alleviates diabetic neuropathic pain by regulating synaptic plasticity of spinal dorsal horn neurons

Pain ◽  
2019 ◽  
Vol 160 (5) ◽  
pp. 1082-1092 ◽  
Author(s):  
Zongqin Zhang ◽  
Xiaobao Ding ◽  
Zhiwei Zhou ◽  
Zhuang Qiu ◽  
Naihao Shi ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Synaptic Plasticity ◽  
Dorsal Horn ◽  
Spinal Dorsal Horn ◽  
Sirtuin 1 ◽  
Diabetic Neuropathic Pain ◽  
Dorsal Horn Neurons ◽  
Spinal Dorsal ◽  
Spinal Dorsal Horn Neurons

scholarly journals Activation of spinal dorsal horn P2Y13 receptors can promote the expression of IL-1β and IL-6 in rats with diabetic neuropathic pain

2018 ◽  
Vol Volume 11 ◽  
pp. 615-628 ◽  
Author(s):  
Rui Zhou ◽  
Tao Xu ◽  
XiaoHong Liu ◽  
YuanShou Chen ◽  
DeYing Kong ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Dorsal Horn ◽  
Spinal Dorsal Horn ◽  
Diabetic Neuropathic Pain ◽  
Spinal Dorsal

scholarly journals Sanguinarine Attenuates Neuropathic Pain in a Rat Model of Chronic Constriction Injury

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ping Li ◽  
Yan-Xiu Wang ◽  
Guang Yang ◽  
Zun-Cheng Zheng ◽  
Chao Yu
Keyword(s):  
Neuropathic Pain ◽  
Dorsal Horn ◽  
P38 Mapk ◽  
Spinal Dorsal Horn ◽  
Chronic Constriction Injury ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Withdrawal Threshold ◽  
Spinal Dorsal ◽  
Plant Medicine

Objective. There is still no effective treatment of neuropathic pain. Sanguinarine is a natural plant medicine with anti-inflammatory effects, but its effect on neuropathic pain remains unclear. This study was aimed at investigating the potential of sanguinarine to attenuate neuropathic pain. Methods. Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve. Rats were randomly divided into several groups: sham, CCI, CCI+SG (1.00 mg/kg), CCI+SG (2.50 mg/kg), and CCI+SG (6.25 mg/kg). SG was injected intraperitoneally from the day of surgery every three days. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were recorded before surgery and on days 1, 3, 7, and 14 after surgery. The microglia in the spinal dorsal horn were examined by immunofluorescence. p38 MAPK expression in the spinal dorsal horn was detected by PCR and Western blot analysis. Cytokine levels in the spinal dorsal horn were measured by ELISA. Results. MWT and TWL were significantly reduced in the CCI group, but sanguinarine recovered MWT and TWL in the CCI group. In addition, sanguinarine inhibited the activation of microglia and decreased the expression of p-p38 and TNF-α, IL-1β, and IL-6 in the spinal dorsal horn of the CCI group in a dose-dependent manner. Conclusions. Our results suggest that sanguinarine can attenuate neuropathic pain via inhibiting the activation of microglia and the activation of the p38 MAPK signaling pathway.

scholarly journals Downregulation of Metallothionein-2 Contributes to Oxaliplatin-induced Neuropathic Pain

2020 ◽  
Author(s):  
Xuelin Huang ◽  
Jie Deng ◽  
Ting Xu ◽  
Wenjun Xin ◽  
Yuehong Zhang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Neuropathic Pain ◽  
Dorsal Horn ◽  
Spinal Dorsal Horn ◽  
Genetic Alterations ◽  
Mrna Levels ◽  
Spinal Cord Neurons ◽  
Spinal Dorsal ◽  
Dorsal Horns ◽  
Prevention And Treatment

Abstract Background We previously reported a correlation between small doses of oxaliplatin penetrating onto the spinal cord and acute pain after chemotherapy. Here we propose that MT2 within the spinal dorsal horns participates the development of oxaliplatin-induced neuropathic pain and may be a pharmacological target for the prevention and treatment of chemotherapy-induced peripheral neuropathy (CIPN). Methods The rat model of CIPN was established by a 5 consecutive injection of oxaliplatin (0.4 mg/ 100 g/ day). Genetic restoration or inhibition of neuron-specific metallothionein-2 was implemented 21 days before oxaliplatin treatment. Mechanical allodynia and locomotor activity were assayed. Cell-specific expression of metallothionein-2, the mRNA levels of pro-inflammatory cytokines, nuclear translocation of NF-κB, the protein levels of expression of IκB-α, and interaction between IκB-α and P65 were evaluated in the spinal dorsal horns. Also, in vitro interaction of sequentially deleted IκB-α promoter with metallothionein-2 was used to assess the signal transduction mechanism. Results We found that oxaliplatin induced downregulation of metallothionein-2 in rat spinal cord neurons. By contrast, genetic restoration of metallothionein-2 in the spinal dorsal horn neuron blocked and reversed neuropathic pain in oxaliplatin-treated rats of both sexes, whereas genetic inhibition of metallothionein-2 triggered neuropathic pain in normal rats. No locomotor impairment was observed after the genetic alterations of metallothionein-2. At the molecular level, metallothionein-2 modulated oxaliplatin-induced neuroinflammation, activation of NF-κB, and transcriptional expression of IκB-α promoter, and these processes could be blocked by genetic restoration of metallothionein-2 in the spinal dorsal horn neurons. Conclusions Metallothionein-2 is a potential target for the prevention and treatment of CIPN. A reduction of NF-κB activation and inflammatory responses by enhancing the transcription of IκB-α promoter is proposed in the mechanism.

scholarly journals Downregulation of metallothionein-2 contributes to oxaliplatin-induced neuropathic pain

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Xuelin Huang ◽  
Jie Deng ◽  
Ting Xu ◽  
Wenjun Xin ◽  
Yuehong Zhang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Neuropathic Pain ◽  
Locomotor Activity ◽  
Dorsal Horn ◽  
Spinal Dorsal Horn ◽  
Genetic Alterations ◽  
Mrna Levels ◽  
Spinal Dorsal ◽  
Dorsal Horns ◽  
Prevention And Treatment

Abstract Background We previously reported a correlation between small doses of oxaliplatin penetrating onto the spinal cord and acute pain after chemotherapy. Here, we propose that MT2 within the spinal dorsal horns participates in the development of oxaliplatin-induced neuropathic pain and may be a pharmacological target for the prevention and treatment of chemotherapy-induced peripheral neuropathy (CIPN). Methods The rat model of CIPN was established by 5 consecutive injections of oxaliplatin (0.4 mg/100 g/day). Genetic restoration of neuron-specific metallothionein-2 was implemented 21 days before oxaliplatin treatment, and also, genetic inhibition by metallothionein-2 siRNA was performed. Mechanical allodynia and locomotor activity were assayed. Cell-specific expression of metallothionein-2, the mRNA levels of pro-inflammatory cytokines, nuclear translocation of NF-κB, the protein levels of expression of IκB-α, and interaction between IκB-α and P65 were evaluated in the spinal dorsal horns. Also, in vitro interaction of sequentially deleted IκB-α promoter with metallothionein-2 was used to assess the signal transduction mechanism. Results We found that oxaliplatin induced downregulation of metallothionein-2 in rat spinal cord neurons. By contrast, genetic restoration of metallothionein-2 in the spinal dorsal horn neuron blocked and reversed neuropathic pain in oxaliplatin-treated rats of both sexes, whereas genetic inhibition of metallothionein-2 triggered neuropathic pain in normal rats. Overall locomotor activity was not impaired after the genetic alterations of metallothionein-2. At the molecular level, metallothionein-2 modulated oxaliplatin-induced neuroinflammation, activation of NF-κB, and inactive transcriptional expression of IκB-α promoter, and these processes could be blocked by genetic restoration of metallothionein-2 in the spinal dorsal horn neurons. Conclusions Metallothionein-2 is a potential target for the prevention and treatment of CIPN. A reduction of NF-κB activation and inflammatory responses by enhancing the transcription of IκB-α promoter is proposed in the mechanism.

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